Figure 13.

Synthetic symbiosis. (a) A cooperative synthetic system involving designed auxotrophic interactions [150]. (b) Synthetic mutualism resulting from niche engineering. Here, two species interact through a metabolic circuit based on carbon and nitrogen exchange. S. cerevisiae (left) metabolizes glucose (C₆H₁₂O₆) releasing carbon dioxide (CO₂), which is then assimilated photosynthetically by C. reinhardtii (right) to release oxygen (O₂). On the other hand, C. reinhardtii metabolizes nitrite (NO₂) and releases ammonia (NH₃) as a nitrogen source for S. cerevisiae [151]. In (c), we display a microscope image of a chimaera zebra fish embryo containing living photosynthetic cells [152,153].